Several commercial products exist in the market today which are used to obtain similar information from a measured system (such as those manufactured by Hagtronics, Venable Industries and DKD Instruments). Such analyzers, however, only provide scalar information (and hence, are incapable of providing phase information), have a limited maximum frequency, are limited to a low number of transmit and receive channels and are costly. What is required is a small, multi-channel, wide-band network analyzer which maintains phase information, allows for inverse fast Fourier transforms to product time responses and is able to generate system information not discernable from the system's magnitude response alone.
Accordingly, it is an object of the present invention to provide a method for real-time network analysis of a system to determine the health or operational state of individual components forming the system and which allows prompt action to be taken in the event of a detected problem.
It is also an object of the present invention to provide a method for real-time analysis of a system which measures system responses using any arrangement of transmitters and receivers, measures system network phase and magnitude transfer functions, measures the transfer function of passive or active filters, measures closed-loop control system phase and magnitude, measures the system's DC gain, open loop bandwidth and phase margin of amplifiers, measures impedance versus frequency of selected system components, measures system resonances, characterizes phase lock loops, measures performance of nonlinear system components (such as signal mixers), determines the phase and noise characteristics of a system and measures other non-linear system characteristics.
It is a further object of the present invention to provide a multiple channel phase coherent, swept-frequency network analyzer which accurately maintains phase integrity of system data, provides enhanced measurement capabilities, is low cost, is small, requires low power for operation and is programmable in frequency, step size, bandwidth and gain.
It is a further object of the present invention to provide a network analyzer having a plurality of pure sinusoidal transmit and measurement channels, the network analyzer maintaining phase integrity between the transmitted signal and the measured signal so that an operational analysis can be executed on the measured signal.
It is also an object of the present invention to provide a network analyzer having a plurality of pure sinusoidal transmit and measurement channels, the network analyzer minimizing direct current drive while enhancing dynamic range of measurements.
It is a further object of the present invention to provide a network analyzer having a plurality of pure sinusoidal transmit and measurement channels, the network analyzer measuring predefined signals by mixing the received signal with a reference, phase-shifted transmit signal and the in-phase transmitted signal.
It is also an object of the present invention to provide a portable system analyzer which measures system responses using any arrangement of transmitters and receivers, measures system network phase and magnitude transfer functions, measures the transfer function of passive or active filters, measures closed-loop control system phase and magnitude, measures the system's DC gain, open loop bandwidth and phase margin of amplifiers, measures impedance versus frequency of selected system components, measures system resonances, characterizes phase lock loops, measures performance of nonlinear system components (such as signal mixers), determines the phase and noise characteristics of a system and measures non-linear system characteristics.
Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those of skill in the art upon examination of the following description or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.